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ADV7612 HDCP Encryption Status

Varun
on Aug 2, 2014

Hi,

I have an ADV7612 without the HDCP core as my company is not licensed for HDCP. As such the part outputs a black raster when encrypted HDMI is input. However I'd like to let users know when an HDCP signal is present, and I see that there is a register called HDMI_CONTENT_ENCRYPTED - Main Addr, Reg Addr 0x05[6]. However this register always tells me that the input is unencrypted. I'm guessing that this part has the HDCP core depopulated, and as such all of these registers are non-functional? Can someone please clarify that there is no way of determining HDCP presence on a non-hdcp enabled ADV7612?

Thanks!

--Varun

  • 0
    •  Analog Employees 
    on Aug 2, 2014 7:26 AM

    Hi Varun,

    The registers should act the same between HDCP ADV7612 and non-HDCP ADV7612.

    However, consumer electronic devices tend to disable HDMI output when HDCP authentication does not complete.

    This is discussed a bit more in this thread:

    Re: re. ADV7604.  Detecting HDCP with non-HDCP part.

    Can you confirm what your source device is doing?

    -Matt

  • 0 on Aug 5, 2014 7:34 PM

    Hi Matt,

    Thanks for getting back to me. The source device is a Blu-ray player with HDMI output. It continues to play a movie, even while I see a black raster.

    I have a follow-up question actually. If the source doesn't disable its output & continues to output video despite our lack of HDCP support, does the ADV part output a black raster? I guess my question is, is it the responsibility of the source to detect our EDID & disable video, or is it our responsibility as a sink? Or both?

    Thanks,

    --Varun

  • 0 on Aug 5, 2014 7:48 PM

    After reading the other thread, I think I have a better handle on how this works now. Until now I'd assumed that the part itself was blocking video from passing, but it seems this is very much source-dependent. Unfortunately I'm not using the eval board, but I can easily check any of the adv registers. Do you have any you'd like me to check?

    Like Dan in the other thread, my goal was to inform the user when an encrypted signal was input, but if the source disabled the output or puts out a black raster & doesn't state that the signal is encrypted, I suppose it's impossible for the sink to know this.

  • 0 on Aug 5, 2014 8:17 PM

    Hi Matt,

    Registers are as follows:

    * ADV7612 IO map 0x42 = 0x14

    * ADV7612 IO map 0x6A = 0x53

    * ADV7612 HDMI map 0x04 = 0x23

    So it looks like everything is locked & no errors are being reported. It must be the blu ray player outputting the black raster. It's certainly a bit disconcerting as the behavior with various sources is unknown, dependent on the source. I feel like they should have included a pre-defined functionality in the HDMI spec for cases like these!

    --Varun

    Edit: Just noticed you want HDMI 0x05, value is: 0xB0

  • 0
    •  Analog Employees 
    on Aug 5, 2014 8:41 PM

    Hi Varun,

    I'm guessing the Blu-ray player is outputting a black screen due to HDCP authentication fail.

    Are you using the software driver to configure the EVAL-ADV7612-7511P? We can check some registers easily with the "stat" command.

    -Matt